The present invention relates to a copper-based polishing composition, a method for manufacturing a semiconductor device, a polishing composition, an aluminum-based metal polishing composition, and a tungsten-based metal polishing composition.
In the step of forming a wiring layer, which is one step in the process for manufacturing a semiconductor device, etch back technique is adopted for the purpose of overcoming the difference in level of its surface. This etch back technique is a manner of forming a trench in a form of wiring in an insulating film on a semiconductor substrate, depositing a Cu film on the insulating film including the trench, using a polishing machine and a polishing composition to polish the Cu film, thereby causing the Cu film to remain only inside the trench to form an embedded wiring layer.
Incidentally, as the polishing composition, hitherto a composition wherein an abrasive grain such as colloidal silica is dispersed into pure water has been used. However, in the case in which the Cu film deposited on the substrate is polished by supplying the polishing composition to a polishing pad of a polishing machine and simultaneously applying a predetermined load to the polishing pad, mechanical polishing caused by the abrasive grain and the polishing pad is merely applied to the Cu film. For this reason, there arises a problem that the polishing rate is low, that is, 10 nm/minute.
On the other hand, J. Electrochem. Soc., Vol. 138. No. 11. 3460 (1991), VMIC Conference, ISMIC-101/92/0156 (1992) or VMIC Conference, ISMIC-102/93/0205 (1993) discloses a composition for polishing a Cu film or a Cu alloy film, comprising a slurry of amine-type colloidal silica, or a slurry wherein K3Fe(CN)6, K4(CN)6 or Co(NO3)2 is added.
However, concerning the aforementioned polishing composition, there is no difference in a rate of etching a Cu film between the step of immersing and the step of polishing. Consequently, if a Cu wiring layer inside the trench contacts the polishing composition after the aforementioned etch back step, the Cu wiring layer is further etched by the polishing composition because there is no difference in the rate of etching the Cu film between the step of immersing and the step of polishing. Therefore, the surface level of the Cu wiring layer inside the trenches becomes lower than the surface of the insulating film. Thus, it becomes difficult that the wiring layer having the same level as the surface of the insulating film is formed, so that its flatness is damaged. Moreover, the embedded Cu wiring layer thus formed has a higher resistance than the Cu wiring layer embedded so as to have the same level as the insulating film surface.
Jpn. Pat. Appln. KOKAI Publication No. 10-44047 describes a polishing slurry, comprising an aqueous medium, an abrasive, an oxidizing agent such as a peroxide, and an organic acid such as lactic acid. The oxidizing agent in this polishing slurry has a function of oxidizing a layer of a metal such as copper on an insulating film to heighten a removing rate in mechanical polishing, and the organic acid has a function of heightening selectivity about the polishing rate of the oxidizing agent.
Jpn. Pat. Appln. KOKAI Publication No. 9-55363 discloses a copper-based metal polishing composition comprising a water-soluble organic acid, such as 2-quinoline carboxylic acid, that is a capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper; an abrasive grain; an oxidizing agent; and water.
An object of the present invention is to provide a copper-based metal polishing composition having an increased rate of polishing copper (Cu) or copper alloy (Cu alloy) by improving the copper-based metal polishing composition disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-55363 described above.
Another object of the present invention is to provide a method for manufacturing a semiconductor device which makes it possible to form at least one member for embedment selected from a trench and an opening in an insulating film on a semiconductor substrate and then subject a conductive material film comprising copper (Cu) or Copper alloy (Cu alloy) formed on the insulating film to etch back treatment for a short time and further to form a conductive member such as an embedded wiring layer having the same level as the surface of the insulating film and exhibiting high accuracy.
Still another object of the present invention is to provide a polishing composition making it possible to polish a metal film, and suppress generation of injuries on the polished surface.
A further object of the present invention is to provide a polishing composition making it possible to polish a metal film comprising Cu or the like at a practical rate, and suppress generation of injuries on the polished surface.
An additional object of the present invention is to provide a method for manufacturing a semiconductor device which makes it possible to form at least one member for embedment selected from a trench and an opening in an insulating film on a semiconductor substrate and then subject a conductive material film comprising copper (Cu) or Copper alloy (Cu alloy) formed on the insulating film to etch back treatment for a short time and further to form a conductive member such as an embedded wiring layer having the same level as the surface of the insulating film, exhibiting high accuracy and causing generation of injuries on its polished surface to be suppressed.
An additional object of the present invention is to provide a method for manufacturing a semiconductor device which makes it possible to form a wiring layer which can be etched back for a short time and has a dual damascene structure with a high precision by making a trench and an opening in an insulating film on a semiconductor substrate, depositing a conductive material film comprising copper (Cu) or copper alloy (Cu alloy) on the insulating film, and subsequently performing polishing.
An additional object of the present invention is to provide a method for manufacturing a semiconductor device which makes it possible to form a high-precision multilayer wiring composed mainly of copper by etch back for a short time.
According to the present invention, provided is a copper-based metal polishing composition, comprising a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper; at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid; an abrasive grain; an oxidizing agent; and water.
Also, according to the present invention, provided is a method for manufacturing a semiconductor device, comprising the steps of:
forming at least one member for embedment selected from an opening corresponding to a shape of a via fill and a trench corresponding to a shape of a wiring layer in an insulating film on a semiconductor substrate;
forming a conductive material film comprising copper or copper alloy on the insulating film including the member; and
polishing the conductive material film by using a polishing composition comprising a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid, an abrasive grain, an oxidizing agent and water, thereby forming at least one conductive member selected from a wiring layer and a via fill in the member for embedment.
Furthermore, according to the present invention, provided is a polishing composition, comprising colloidal alumina and water.
Furthermore, according to the present invention, is provided is a copper-based metal polishing composition comprising a water-soluble organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper; an oxidizing agent; colloidal alumina and water.
Additionally, according to the present invention, provided is a method for manufacturing a semiconductor device, comprising the steps of:
forming at least one member for embedment selected from an opening corresponding to a shape of a via fill and a trench corresponding to a shape of a wiring layer in an insulating film on a semiconductor substrate;
forming a conductive material film comprising copper or copper alloy on the insulating film including the member; and
polishing the conductive material film by using a polishing composition comprising a water-soluble organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, an oxidizing agent, colloidal alumina and water, thereby forming at least one conductive member selected from a wiring layer and a via fill in the member for embedment.
Moreover, according to the present invention, provided is an aluminum-based metal polishing composition, comprising at least one polishing promoter selected from trimethyl ammonium hydroxide, trimethyl hydroxide, a mixed acid of phosphoric acid, sulfuric acid and acetic acid, and ferric chloride; an oxidizing agent; colloidal alumina; and water.
Besides, according to the present invention, provided is a tungsten-based metal polishing composition, comprising at least one polishing promoter selected from ferric chloride and ferric nitrate; an oxidizing agent; colloidal alumina; and water.
Furthermore, according to the present invention, provided is a method for manufacturing a semiconductor device, comprising the steps of:
forming a trench corresponding to a shape of a wiring layer in an insulating film on a semiconductor substrate, and forming an opening reached to a surface of the semiconductor substrate in the insulating film portion which is positioned at a part of the bottom of the trench;
forming a conductive material film comprising copper or copper alloy on the insulating film including the trench and the opening; and
polishing the conductive material film by using a polishing composition comprising a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid, an abrasive grain, an oxidizing agent, and water, thereby forming wiring having a dual damascene structure in the opening and trench.
Furthermore, according to the present invention, provided is a method for manufacturing a semiconductor device, comprising the steps of:
forming at least a first opening corresponding to a shape of a first via fill in a first insulating film on a semiconductor substrate, forming a first conductive material film comprising copper or copper alloy on the first insulating film including the opening;
polishing the first conductive material film by using a polishing composition comprising a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid, an abrasive grain, an oxidizing agent, and water, thereby forming the first via fill in the first opening;
forming a second insulating film on the first insulating film including the first via fill;
forming a second opening corresponding to a shape of a second via fill reached to at least the first via fill in the second insulating film;
forming a second conductive material film comprising copper or copper alloy on the second insulating film including the second opening; and
polishing the second conductive material film by using a second polishing composition comprising a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid, an abrasive grain, an oxidizing agent, and water, thereby forming the second via fill in the second opening.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.